Tomioka

What to know

Tomioka (富岡), a city in southwestern Gunma Prefecture, is home to Japan's first modern silk factory, established in 1872. The Tomioka Silk Mill became a model for other silk mills across the country, helping modernize Japan's silk industry during the Meiji Period—a time of sweeping reforms aimed at catching up with the West. The mill was instrumental in making textiles Japan's leading industry for decades, fueling economic growth.

Not only is the Tomioka Silk Mill Japan's oldest modern silk reeling factory, but it was also one of the world's largest at the time of its construction. Thanks to innovations introduced at the mill, raw silk became a major export commodity, and Tomioka's silk earned a global reputation for high quality. The original buildings are well preserved and form the centerpiece of four silk-related sites in Gunma Prefecture that were inscribed as a UNESCO World Heritage Site in 2014.

The other three sites are located in nearby cities: the Tajima Yahei Sericulture Farm, which excelled in silkworm egg production research; the Arafune Cold Storage, which used natural cooling to store silkworm eggs and enable multiple harvests per year; and the Takayama-sha Sericulture School, which introduced major improvements in raising silkworms to produce cocoons for processing at the Tomioka mill.